NOAA dive team returns from the northern Hawaiian Islands after removing more than 57 tons of ghost nets from coral reefs--but there's much more work to be done.

"A team of NOAA divers has just returned from a month-long mission to pull up marine garbage from the ocean floor around Hawaii’s Papahānaumokuākea Marine National Monument, a UNESCO World Heritage site and one of the world’s biggest marine conservation areas.

What they found was “shocking,” said Mark Manuel, the mission’s chief scientist and operations manager for the NOAA Fisheries Coral Reef Ecosystem Division, especially for such a remote and untouched place, he said."